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What every hospitalist should know
With the prevalence of obesity worldwide topping 650 million people1 and nearly 40% of U.S. adults having obesity,2 bariatric surgery is increasingly used to treat this disease and its associated comorbidities.
The American Society for Metabolic & Bariatric Surgery estimates that 228,000 bariatric procedures were performed on Americans in 2017, up from 158,000 in 2011.3 Despite lowering the risks of diabetes, stroke, myocardial infarction, cancer, and all-cause mortality,4 bariatric surgery is associated with increased health care use. Neovius et al. found that people who underwent bariatric surgery used 54 mean cumulative hospital days in the 20 years following their procedures, compared with just 40 inpatient days used by controls.5
Although hospitalists are caring for increasing numbers of patients who have undergone bariatric surgery, many of us may not be aware of some of the things that can lead to hospitalization or otherwise affect inpatient medical care. Here are a few points to keep in mind the next time you care for an inpatient with prior bariatric surgery.
Pharmacokinetics change after surgery
Gastrointestinal anatomy necessarily changes after bariatric surgery and can affect the oral absorption of drugs. Because gastric motility may be impaired and the pH in the stomach is increased after bariatric surgery, the disintegration and dissolution of immediate-release solid pills or caps may be compromised.
It is therefore prudent to crush solid forms or switch to liquid or chewable formulations of immediate-release drugs for the first few weeks to months after surgery. Enteric-coated or long-acting drug formulations should not be crushed and should generally be avoided in patients who have undergone bypass procedures such as Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion with duodenal switch (BPD/DS), as they can demonstrate either enhanced or diminished absorption (depending on the drug).
Reduced intestinal transit times and changes in intestinal pH can alter the absorption of certain drugs as well, and the expression of some drug transporter proteins and enzymes such as the CYP3A4 variant of cytochrome P450 – which is estimated to metabolize up to half of currently available drugs – varies between the upper and the lower small intestine, potentially leading to increased bioavailability of medications metabolized by this enzyme in patients who have undergone bypass surgeries.
Interestingly, longer-term studies have reexamined drug absorption in patients 2-4 years after RYGB and found that initially-increased drug plasma levels often return to preoperative levels or even lower over time,6 likely because of adaptive changes in the GI tract. Because research on the pharmacokinetics of individual drugs after bariatric surgery is lacking, the hospitalist should be aware that the bioavailability of oral drugs is often altered and should monitor patients for the desired therapeutic effect as well as potential toxicities for any drug administered to postbariatric surgery patients.
Finally, note that nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, and corticosteroids should be avoided after bariatric surgery unless the benefit clearly outweighs the risk, as they increase the risk of ulcers even in patients without underlying surgical disruptions to the gastric mucosa.
Micronutrient deficiencies are common and can occur at any time
While many clinicians recognize that vitamin deficiencies can occur after weight loss surgeries which bypass the duodenum, such as the RYGB or the BPD/DS, it is important to note that vitamin and mineral deficiencies occur commonly even in patients with intact intestinal absorption such as those who underwent sleeve gastrectomy (SG) and even despite regained weight due to greater volumes of food (and micronutrient) intake over time.
The most common vitamin deficiencies include iron, vitamin B12, thiamine (vitamin B1), and vitamin D, but deficiencies in other vitamins and minerals may found as well. Anemia, bone fractures, heart failure, and encephalopathy can all be related to postoperative vitamin deficiencies. Most bariatric surgery patients should have micronutrient levels monitored on a yearly basis and should be taking at least a multivitamin with minerals (including zinc, copper, selenium and iron), a form of vitamin B12, and vitamin D with calcium supplementation. Additional supplements may be appropriate depending on the type of surgery the patient had or whether a deficiency is found.
The differential diagnosis for abdominal pain after bariatric surgery is unique
While the usual suspects such as diverticulitis or gastritis should be considered in postbariatric surgery patients just as in others, a few specific complications can arise after weight loss surgery.
Marginal ulcerations (ulcers at the surgical anastomotic sites) have been reported in up to a third of patients complaining of abdominal pain or dysphagia after RYGB, with tobacco, alcohol, or NSAID use conferring even greater risk.7 Early upper endoscopy may be warranted in symptomatic patients.
Small bowel obstruction (SBO) may occur due to surgical adhesions as in other patients, but catastrophic internal hernias with associated volvulus can occur due to specific anatomical defects that are created by the RYGB and BPD/DS procedures. CT imaging is insensitive and can miss up to 30% of these cases,8 and nasogastric tubes placed blindly for decompression of an SBO can lead to perforation of the end of the alimentary limb at the gastric pouch outlet, so post-RYGB or BPD/DS patients presenting with signs of small bowel obstruction should have an early surgical consult for expeditious surgical management rather than a trial of conservative medical management.9
Cholelithiasis is a very common postoperative complication, occurring in about 25% of SG patients and 32% of RYGB patients in the first year following surgery. The risk of gallstone formation can be significantly reduced with the postoperative use of ursodeoxycholic acid.10
Onset of abdominal cramping, nausea and diarrhea (sometimes accompanied by vasomotor symptoms) within 15-60 minutes of eating may be due to early dumping syndrome. Rapid delivery of food from the gastric pouch into the small intestine causes the release of gut peptides and an osmotic fluid shift into the intestinal lumen that can trigger these symptoms even in patients with a preserved pyloric sphincter, such as those who underwent SG. Simply eliminating sugars and simple carbohydrates from the diet usually resolves the problem, and eliminating lactose can often be helpful as well.
Postprandial hyperinsulinemic hypoglycemia (“late dumping syndrome”) can develop years after surgery
Vasomotor symptoms such as flushing/sweating, shaking, tachycardia/palpitations, lightheadedness, or difficulty concentrating occurring 1-3 hours after a meal should prompt blood glucose testing, as delayed hypoglycemia can occur after a large insulin surge.
Most commonly seen after RYGB, late dumping syndrome, like early dumping syndrome, can often be managed by eliminating sugars and simple carbohydrates from the diet. The onset of late dumping syndrome has been reported as late as 8 years after surgery,11 so the etiology of symptoms can be elusive. If the diagnosis is unclear, an oral glucose tolerance test may be helpful.
Alcohol use disorder is more prevalent after weight loss surgery
Changes to the gastrointestinal anatomy allow for more rapid absorption of ethanol into the bloodstream, making the drug more potent in postop patients. Simultaneously, many patients who undergo bariatric surgery have a history of using food to buffer negative emotions. Abruptly depriving them of that comfort in the context of the increased potency of alcohol could potentially leave bariatric surgery patients vulnerable to the development of alcohol use disorder, even when they did not misuse alcohol preoperatively.
Of note, alcohol misuse becomes more prevalent after the first postoperative year.12 Screening for alcohol misuse on admission to the hospital is wise in all cases, but perhaps even more so in the postbariatric surgery patient. If a patient does report excessive alcohol use, keep possible thiamine deficiency in mind.
The risk of suicide and self-harm increases after bariatric surgery
While all-cause mortality rates decrease after bariatric surgery compared with matched controls, the risk of suicide and nonfatal self-harm increases.
About half of bariatric surgery patients with nonfatal events have substance misuse.13 Notably, several studies have found reduced plasma levels of SSRIs in patients after RYGB,6 so pharmacotherapy for mood disorders could be less effective after bariatric surgery as well. The hospitalist could positively impact patients by screening for both substance misuse and depression and by having a low threshold for referral to a mental health professional.
As we see ever-increasing numbers of inpatients who have a history of bariatric surgery, being aware of these common and important complications can help today’s hospitalist provide the best care possible.
Dr. Kerns is a hospitalist and codirector of bariatric surgery at the Washington DC VA Medical Center.
References
1. Obesity and overweight. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight. Published Feb 16, 2018.
2. Hales CM et al. Prevalence of obesity among adults and youth: United States, 2015-2016. NCHS data brief, no 288. Hyattsville, MD: National Center for Health Statistics. 2017.
3. Estimate of Bariatric Surgery Numbers, 2011-2018. ASMBS.org. Published June 2018.
4. Sjöström L. Review of the key results from the Swedish Obese Subjects (SOS) trial – a prospective controlled intervention study of bariatric surgery. J Intern Med. 2013 Mar;273(3):219-34. doi: 10.1111/joim.12012.
5. Neovius M et al. Health care use during 20 years following bariatric surgery. JAMA. 2012 Sep 19; 308(11):1132-41. doi: 10.1001/2012.jama.11792.
6. Azran C. et al. Oral drug therapy following bariatric surgery: An overview of fundamentals, literature and clinical recommendations. Obes Rev. 2016 Nov;17(11):1050-66. doi: 10.1111/obr.12434.
7. El-hayek KM et al. Marginal ulcer after Roux-en-Y gastric bypass: What have we really learned? Surg Endosc. 2012 Oct;26(10):2789-96. Epub 2012 Apr 28. (Abstract presented at Society of American Gastrointestinal and Endoscopic Surgeons 2012 annual meeting, San Diego.) 8. Iannelli A et al. Internal hernia after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Obes Surg. 2006;16:1265-71. doi: 10.1381/096089206778663689.
9. Lim R et al. Early and late complications of bariatric operation. Trauma Surg Acute Care Open. 2018 Oct 9;3(1): e000219. doi: 10.1136/tsaco-2018-000219.
10. Coupaye M et al. Evaluation of incidence of cholelithiasis after bariatric surgery in subjects treated or not treated with ursodeoxycholic acid. Surg Obes Relat Dis. 2017;13(4):681-5. doi: 10.1016/j.soard.2016.11.022.
11. Eisenberg D et al. ASMBS position statement on postprandial hyperinsulinemic hypoglycemia after bariatric surgery. Surg Obes Relat Dis. 2017 Mar;13(3):371-8. doi: 10.1016/j.soard.2016.12.005.
12. King WC et al. Prevalence of alcohol use disorders before and after bariatric surgery. JAMA. 2012 Jun 20;307(23):2516-25. doi: 10.1001/jama.2012.6147.
13. Neovius M et al. Risk of suicide and non-fatal self-harm after bariatric surgery: Results from two matched cohort studies. Lancet Diabetes Endocrinol. 2018 Mar;6(3):197-207. doi: 10.1016/S2213-8587(17)30437-0.
What every hospitalist should know
What every hospitalist should know
With the prevalence of obesity worldwide topping 650 million people1 and nearly 40% of U.S. adults having obesity,2 bariatric surgery is increasingly used to treat this disease and its associated comorbidities.
The American Society for Metabolic & Bariatric Surgery estimates that 228,000 bariatric procedures were performed on Americans in 2017, up from 158,000 in 2011.3 Despite lowering the risks of diabetes, stroke, myocardial infarction, cancer, and all-cause mortality,4 bariatric surgery is associated with increased health care use. Neovius et al. found that people who underwent bariatric surgery used 54 mean cumulative hospital days in the 20 years following their procedures, compared with just 40 inpatient days used by controls.5
Although hospitalists are caring for increasing numbers of patients who have undergone bariatric surgery, many of us may not be aware of some of the things that can lead to hospitalization or otherwise affect inpatient medical care. Here are a few points to keep in mind the next time you care for an inpatient with prior bariatric surgery.
Pharmacokinetics change after surgery
Gastrointestinal anatomy necessarily changes after bariatric surgery and can affect the oral absorption of drugs. Because gastric motility may be impaired and the pH in the stomach is increased after bariatric surgery, the disintegration and dissolution of immediate-release solid pills or caps may be compromised.
It is therefore prudent to crush solid forms or switch to liquid or chewable formulations of immediate-release drugs for the first few weeks to months after surgery. Enteric-coated or long-acting drug formulations should not be crushed and should generally be avoided in patients who have undergone bypass procedures such as Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion with duodenal switch (BPD/DS), as they can demonstrate either enhanced or diminished absorption (depending on the drug).
Reduced intestinal transit times and changes in intestinal pH can alter the absorption of certain drugs as well, and the expression of some drug transporter proteins and enzymes such as the CYP3A4 variant of cytochrome P450 – which is estimated to metabolize up to half of currently available drugs – varies between the upper and the lower small intestine, potentially leading to increased bioavailability of medications metabolized by this enzyme in patients who have undergone bypass surgeries.
Interestingly, longer-term studies have reexamined drug absorption in patients 2-4 years after RYGB and found that initially-increased drug plasma levels often return to preoperative levels or even lower over time,6 likely because of adaptive changes in the GI tract. Because research on the pharmacokinetics of individual drugs after bariatric surgery is lacking, the hospitalist should be aware that the bioavailability of oral drugs is often altered and should monitor patients for the desired therapeutic effect as well as potential toxicities for any drug administered to postbariatric surgery patients.
Finally, note that nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, and corticosteroids should be avoided after bariatric surgery unless the benefit clearly outweighs the risk, as they increase the risk of ulcers even in patients without underlying surgical disruptions to the gastric mucosa.
Micronutrient deficiencies are common and can occur at any time
While many clinicians recognize that vitamin deficiencies can occur after weight loss surgeries which bypass the duodenum, such as the RYGB or the BPD/DS, it is important to note that vitamin and mineral deficiencies occur commonly even in patients with intact intestinal absorption such as those who underwent sleeve gastrectomy (SG) and even despite regained weight due to greater volumes of food (and micronutrient) intake over time.
The most common vitamin deficiencies include iron, vitamin B12, thiamine (vitamin B1), and vitamin D, but deficiencies in other vitamins and minerals may found as well. Anemia, bone fractures, heart failure, and encephalopathy can all be related to postoperative vitamin deficiencies. Most bariatric surgery patients should have micronutrient levels monitored on a yearly basis and should be taking at least a multivitamin with minerals (including zinc, copper, selenium and iron), a form of vitamin B12, and vitamin D with calcium supplementation. Additional supplements may be appropriate depending on the type of surgery the patient had or whether a deficiency is found.
The differential diagnosis for abdominal pain after bariatric surgery is unique
While the usual suspects such as diverticulitis or gastritis should be considered in postbariatric surgery patients just as in others, a few specific complications can arise after weight loss surgery.
Marginal ulcerations (ulcers at the surgical anastomotic sites) have been reported in up to a third of patients complaining of abdominal pain or dysphagia after RYGB, with tobacco, alcohol, or NSAID use conferring even greater risk.7 Early upper endoscopy may be warranted in symptomatic patients.
Small bowel obstruction (SBO) may occur due to surgical adhesions as in other patients, but catastrophic internal hernias with associated volvulus can occur due to specific anatomical defects that are created by the RYGB and BPD/DS procedures. CT imaging is insensitive and can miss up to 30% of these cases,8 and nasogastric tubes placed blindly for decompression of an SBO can lead to perforation of the end of the alimentary limb at the gastric pouch outlet, so post-RYGB or BPD/DS patients presenting with signs of small bowel obstruction should have an early surgical consult for expeditious surgical management rather than a trial of conservative medical management.9
Cholelithiasis is a very common postoperative complication, occurring in about 25% of SG patients and 32% of RYGB patients in the first year following surgery. The risk of gallstone formation can be significantly reduced with the postoperative use of ursodeoxycholic acid.10
Onset of abdominal cramping, nausea and diarrhea (sometimes accompanied by vasomotor symptoms) within 15-60 minutes of eating may be due to early dumping syndrome. Rapid delivery of food from the gastric pouch into the small intestine causes the release of gut peptides and an osmotic fluid shift into the intestinal lumen that can trigger these symptoms even in patients with a preserved pyloric sphincter, such as those who underwent SG. Simply eliminating sugars and simple carbohydrates from the diet usually resolves the problem, and eliminating lactose can often be helpful as well.
Postprandial hyperinsulinemic hypoglycemia (“late dumping syndrome”) can develop years after surgery
Vasomotor symptoms such as flushing/sweating, shaking, tachycardia/palpitations, lightheadedness, or difficulty concentrating occurring 1-3 hours after a meal should prompt blood glucose testing, as delayed hypoglycemia can occur after a large insulin surge.
Most commonly seen after RYGB, late dumping syndrome, like early dumping syndrome, can often be managed by eliminating sugars and simple carbohydrates from the diet. The onset of late dumping syndrome has been reported as late as 8 years after surgery,11 so the etiology of symptoms can be elusive. If the diagnosis is unclear, an oral glucose tolerance test may be helpful.
Alcohol use disorder is more prevalent after weight loss surgery
Changes to the gastrointestinal anatomy allow for more rapid absorption of ethanol into the bloodstream, making the drug more potent in postop patients. Simultaneously, many patients who undergo bariatric surgery have a history of using food to buffer negative emotions. Abruptly depriving them of that comfort in the context of the increased potency of alcohol could potentially leave bariatric surgery patients vulnerable to the development of alcohol use disorder, even when they did not misuse alcohol preoperatively.
Of note, alcohol misuse becomes more prevalent after the first postoperative year.12 Screening for alcohol misuse on admission to the hospital is wise in all cases, but perhaps even more so in the postbariatric surgery patient. If a patient does report excessive alcohol use, keep possible thiamine deficiency in mind.
The risk of suicide and self-harm increases after bariatric surgery
While all-cause mortality rates decrease after bariatric surgery compared with matched controls, the risk of suicide and nonfatal self-harm increases.
About half of bariatric surgery patients with nonfatal events have substance misuse.13 Notably, several studies have found reduced plasma levels of SSRIs in patients after RYGB,6 so pharmacotherapy for mood disorders could be less effective after bariatric surgery as well. The hospitalist could positively impact patients by screening for both substance misuse and depression and by having a low threshold for referral to a mental health professional.
As we see ever-increasing numbers of inpatients who have a history of bariatric surgery, being aware of these common and important complications can help today’s hospitalist provide the best care possible.
Dr. Kerns is a hospitalist and codirector of bariatric surgery at the Washington DC VA Medical Center.
References
1. Obesity and overweight. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight. Published Feb 16, 2018.
2. Hales CM et al. Prevalence of obesity among adults and youth: United States, 2015-2016. NCHS data brief, no 288. Hyattsville, MD: National Center for Health Statistics. 2017.
3. Estimate of Bariatric Surgery Numbers, 2011-2018. ASMBS.org. Published June 2018.
4. Sjöström L. Review of the key results from the Swedish Obese Subjects (SOS) trial – a prospective controlled intervention study of bariatric surgery. J Intern Med. 2013 Mar;273(3):219-34. doi: 10.1111/joim.12012.
5. Neovius M et al. Health care use during 20 years following bariatric surgery. JAMA. 2012 Sep 19; 308(11):1132-41. doi: 10.1001/2012.jama.11792.
6. Azran C. et al. Oral drug therapy following bariatric surgery: An overview of fundamentals, literature and clinical recommendations. Obes Rev. 2016 Nov;17(11):1050-66. doi: 10.1111/obr.12434.
7. El-hayek KM et al. Marginal ulcer after Roux-en-Y gastric bypass: What have we really learned? Surg Endosc. 2012 Oct;26(10):2789-96. Epub 2012 Apr 28. (Abstract presented at Society of American Gastrointestinal and Endoscopic Surgeons 2012 annual meeting, San Diego.) 8. Iannelli A et al. Internal hernia after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Obes Surg. 2006;16:1265-71. doi: 10.1381/096089206778663689.
9. Lim R et al. Early and late complications of bariatric operation. Trauma Surg Acute Care Open. 2018 Oct 9;3(1): e000219. doi: 10.1136/tsaco-2018-000219.
10. Coupaye M et al. Evaluation of incidence of cholelithiasis after bariatric surgery in subjects treated or not treated with ursodeoxycholic acid. Surg Obes Relat Dis. 2017;13(4):681-5. doi: 10.1016/j.soard.2016.11.022.
11. Eisenberg D et al. ASMBS position statement on postprandial hyperinsulinemic hypoglycemia after bariatric surgery. Surg Obes Relat Dis. 2017 Mar;13(3):371-8. doi: 10.1016/j.soard.2016.12.005.
12. King WC et al. Prevalence of alcohol use disorders before and after bariatric surgery. JAMA. 2012 Jun 20;307(23):2516-25. doi: 10.1001/jama.2012.6147.
13. Neovius M et al. Risk of suicide and non-fatal self-harm after bariatric surgery: Results from two matched cohort studies. Lancet Diabetes Endocrinol. 2018 Mar;6(3):197-207. doi: 10.1016/S2213-8587(17)30437-0.
With the prevalence of obesity worldwide topping 650 million people1 and nearly 40% of U.S. adults having obesity,2 bariatric surgery is increasingly used to treat this disease and its associated comorbidities.
The American Society for Metabolic & Bariatric Surgery estimates that 228,000 bariatric procedures were performed on Americans in 2017, up from 158,000 in 2011.3 Despite lowering the risks of diabetes, stroke, myocardial infarction, cancer, and all-cause mortality,4 bariatric surgery is associated with increased health care use. Neovius et al. found that people who underwent bariatric surgery used 54 mean cumulative hospital days in the 20 years following their procedures, compared with just 40 inpatient days used by controls.5
Although hospitalists are caring for increasing numbers of patients who have undergone bariatric surgery, many of us may not be aware of some of the things that can lead to hospitalization or otherwise affect inpatient medical care. Here are a few points to keep in mind the next time you care for an inpatient with prior bariatric surgery.
Pharmacokinetics change after surgery
Gastrointestinal anatomy necessarily changes after bariatric surgery and can affect the oral absorption of drugs. Because gastric motility may be impaired and the pH in the stomach is increased after bariatric surgery, the disintegration and dissolution of immediate-release solid pills or caps may be compromised.
It is therefore prudent to crush solid forms or switch to liquid or chewable formulations of immediate-release drugs for the first few weeks to months after surgery. Enteric-coated or long-acting drug formulations should not be crushed and should generally be avoided in patients who have undergone bypass procedures such as Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion with duodenal switch (BPD/DS), as they can demonstrate either enhanced or diminished absorption (depending on the drug).
Reduced intestinal transit times and changes in intestinal pH can alter the absorption of certain drugs as well, and the expression of some drug transporter proteins and enzymes such as the CYP3A4 variant of cytochrome P450 – which is estimated to metabolize up to half of currently available drugs – varies between the upper and the lower small intestine, potentially leading to increased bioavailability of medications metabolized by this enzyme in patients who have undergone bypass surgeries.
Interestingly, longer-term studies have reexamined drug absorption in patients 2-4 years after RYGB and found that initially-increased drug plasma levels often return to preoperative levels or even lower over time,6 likely because of adaptive changes in the GI tract. Because research on the pharmacokinetics of individual drugs after bariatric surgery is lacking, the hospitalist should be aware that the bioavailability of oral drugs is often altered and should monitor patients for the desired therapeutic effect as well as potential toxicities for any drug administered to postbariatric surgery patients.
Finally, note that nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, and corticosteroids should be avoided after bariatric surgery unless the benefit clearly outweighs the risk, as they increase the risk of ulcers even in patients without underlying surgical disruptions to the gastric mucosa.
Micronutrient deficiencies are common and can occur at any time
While many clinicians recognize that vitamin deficiencies can occur after weight loss surgeries which bypass the duodenum, such as the RYGB or the BPD/DS, it is important to note that vitamin and mineral deficiencies occur commonly even in patients with intact intestinal absorption such as those who underwent sleeve gastrectomy (SG) and even despite regained weight due to greater volumes of food (and micronutrient) intake over time.
The most common vitamin deficiencies include iron, vitamin B12, thiamine (vitamin B1), and vitamin D, but deficiencies in other vitamins and minerals may found as well. Anemia, bone fractures, heart failure, and encephalopathy can all be related to postoperative vitamin deficiencies. Most bariatric surgery patients should have micronutrient levels monitored on a yearly basis and should be taking at least a multivitamin with minerals (including zinc, copper, selenium and iron), a form of vitamin B12, and vitamin D with calcium supplementation. Additional supplements may be appropriate depending on the type of surgery the patient had or whether a deficiency is found.
The differential diagnosis for abdominal pain after bariatric surgery is unique
While the usual suspects such as diverticulitis or gastritis should be considered in postbariatric surgery patients just as in others, a few specific complications can arise after weight loss surgery.
Marginal ulcerations (ulcers at the surgical anastomotic sites) have been reported in up to a third of patients complaining of abdominal pain or dysphagia after RYGB, with tobacco, alcohol, or NSAID use conferring even greater risk.7 Early upper endoscopy may be warranted in symptomatic patients.
Small bowel obstruction (SBO) may occur due to surgical adhesions as in other patients, but catastrophic internal hernias with associated volvulus can occur due to specific anatomical defects that are created by the RYGB and BPD/DS procedures. CT imaging is insensitive and can miss up to 30% of these cases,8 and nasogastric tubes placed blindly for decompression of an SBO can lead to perforation of the end of the alimentary limb at the gastric pouch outlet, so post-RYGB or BPD/DS patients presenting with signs of small bowel obstruction should have an early surgical consult for expeditious surgical management rather than a trial of conservative medical management.9
Cholelithiasis is a very common postoperative complication, occurring in about 25% of SG patients and 32% of RYGB patients in the first year following surgery. The risk of gallstone formation can be significantly reduced with the postoperative use of ursodeoxycholic acid.10
Onset of abdominal cramping, nausea and diarrhea (sometimes accompanied by vasomotor symptoms) within 15-60 minutes of eating may be due to early dumping syndrome. Rapid delivery of food from the gastric pouch into the small intestine causes the release of gut peptides and an osmotic fluid shift into the intestinal lumen that can trigger these symptoms even in patients with a preserved pyloric sphincter, such as those who underwent SG. Simply eliminating sugars and simple carbohydrates from the diet usually resolves the problem, and eliminating lactose can often be helpful as well.
Postprandial hyperinsulinemic hypoglycemia (“late dumping syndrome”) can develop years after surgery
Vasomotor symptoms such as flushing/sweating, shaking, tachycardia/palpitations, lightheadedness, or difficulty concentrating occurring 1-3 hours after a meal should prompt blood glucose testing, as delayed hypoglycemia can occur after a large insulin surge.
Most commonly seen after RYGB, late dumping syndrome, like early dumping syndrome, can often be managed by eliminating sugars and simple carbohydrates from the diet. The onset of late dumping syndrome has been reported as late as 8 years after surgery,11 so the etiology of symptoms can be elusive. If the diagnosis is unclear, an oral glucose tolerance test may be helpful.
Alcohol use disorder is more prevalent after weight loss surgery
Changes to the gastrointestinal anatomy allow for more rapid absorption of ethanol into the bloodstream, making the drug more potent in postop patients. Simultaneously, many patients who undergo bariatric surgery have a history of using food to buffer negative emotions. Abruptly depriving them of that comfort in the context of the increased potency of alcohol could potentially leave bariatric surgery patients vulnerable to the development of alcohol use disorder, even when they did not misuse alcohol preoperatively.
Of note, alcohol misuse becomes more prevalent after the first postoperative year.12 Screening for alcohol misuse on admission to the hospital is wise in all cases, but perhaps even more so in the postbariatric surgery patient. If a patient does report excessive alcohol use, keep possible thiamine deficiency in mind.
The risk of suicide and self-harm increases after bariatric surgery
While all-cause mortality rates decrease after bariatric surgery compared with matched controls, the risk of suicide and nonfatal self-harm increases.
About half of bariatric surgery patients with nonfatal events have substance misuse.13 Notably, several studies have found reduced plasma levels of SSRIs in patients after RYGB,6 so pharmacotherapy for mood disorders could be less effective after bariatric surgery as well. The hospitalist could positively impact patients by screening for both substance misuse and depression and by having a low threshold for referral to a mental health professional.
As we see ever-increasing numbers of inpatients who have a history of bariatric surgery, being aware of these common and important complications can help today’s hospitalist provide the best care possible.
Dr. Kerns is a hospitalist and codirector of bariatric surgery at the Washington DC VA Medical Center.
References
1. Obesity and overweight. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight. Published Feb 16, 2018.
2. Hales CM et al. Prevalence of obesity among adults and youth: United States, 2015-2016. NCHS data brief, no 288. Hyattsville, MD: National Center for Health Statistics. 2017.
3. Estimate of Bariatric Surgery Numbers, 2011-2018. ASMBS.org. Published June 2018.
4. Sjöström L. Review of the key results from the Swedish Obese Subjects (SOS) trial – a prospective controlled intervention study of bariatric surgery. J Intern Med. 2013 Mar;273(3):219-34. doi: 10.1111/joim.12012.
5. Neovius M et al. Health care use during 20 years following bariatric surgery. JAMA. 2012 Sep 19; 308(11):1132-41. doi: 10.1001/2012.jama.11792.
6. Azran C. et al. Oral drug therapy following bariatric surgery: An overview of fundamentals, literature and clinical recommendations. Obes Rev. 2016 Nov;17(11):1050-66. doi: 10.1111/obr.12434.
7. El-hayek KM et al. Marginal ulcer after Roux-en-Y gastric bypass: What have we really learned? Surg Endosc. 2012 Oct;26(10):2789-96. Epub 2012 Apr 28. (Abstract presented at Society of American Gastrointestinal and Endoscopic Surgeons 2012 annual meeting, San Diego.) 8. Iannelli A et al. Internal hernia after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Obes Surg. 2006;16:1265-71. doi: 10.1381/096089206778663689.
9. Lim R et al. Early and late complications of bariatric operation. Trauma Surg Acute Care Open. 2018 Oct 9;3(1): e000219. doi: 10.1136/tsaco-2018-000219.
10. Coupaye M et al. Evaluation of incidence of cholelithiasis after bariatric surgery in subjects treated or not treated with ursodeoxycholic acid. Surg Obes Relat Dis. 2017;13(4):681-5. doi: 10.1016/j.soard.2016.11.022.
11. Eisenberg D et al. ASMBS position statement on postprandial hyperinsulinemic hypoglycemia after bariatric surgery. Surg Obes Relat Dis. 2017 Mar;13(3):371-8. doi: 10.1016/j.soard.2016.12.005.
12. King WC et al. Prevalence of alcohol use disorders before and after bariatric surgery. JAMA. 2012 Jun 20;307(23):2516-25. doi: 10.1001/jama.2012.6147.
13. Neovius M et al. Risk of suicide and non-fatal self-harm after bariatric surgery: Results from two matched cohort studies. Lancet Diabetes Endocrinol. 2018 Mar;6(3):197-207. doi: 10.1016/S2213-8587(17)30437-0.